The Shiranui Sea, which stretches out from the coast of Minamata City in Kumamoto Prefecture, was once plagued by pollution that decimated its ecosystem. But now, divers from all over the country are rushing to explore its waters. The reason is Makoto Morishita, a diver living in Minamata City. In order to dispel the negative perception of Minamata’s sea, he highlights its charms through the ecology of one rare creature: the Korean seahorse. This seahorse was recognized as a new species in 2017, the first in Japan in 116 years. During their mating season, their unique way of bringing new life into the world captivates all who see it. The miracle of life unfolds in the sea of Minamata, ironically once called a sea of death.